OA21372A - Textured edible protein product derived from insect larvae or worms. - Google Patents

Abstract

The invention relates to a process and a system for producing a textured edible protein product derived from insect larvae or worms. The process comprises a) reducing the insect larvae or worms in size to obtain a pulp, b) mixing the pulp with a hydrocolloid that gelates with metal cations in aqueous solution to form a protein-hydrocolloid slurry, and c) injecting the protein-hydrocolloid slurry into an aqueous solution of a metal cation with a valency of at least 2 to form the textured edible protein product. In step c) the proteinhydrocolloid slurry is jetted under pressure from outside of the aqueous solution of a metal cation with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution, thereby producing flakes of the textured edible protein product in the aqueous solution, in which flakes substantially all hydrocolloid has been gelated with the metal cations.

Description

* Textured edible protein product derived from insect larvae or worms

The présent invention relates to a process for producing a textured edible protein product derived from insect larvae or worms, to a System for continuously producing a textured edible protein product derived from insect larvae or worms, and to a textured edible protein product derived from insect larvae or worms.

Background Art

As the world population grows, so does the need for proteins suitable for consumption. Cattle feedlots are the traditional source of proteins for consumption. However, they require a vast amount of money and energy to raise and feed, to remove waste and to keep them healthy. Worms and insects are a very suitable alternative to cattle feedstock. They offer an economical and sustainable solution to current issues with the production and distribution of proteins for consumption. Notably insect farming is much cheaper and requires much less energy than cattle farming. Much of this efficiency is a resuit of insects being exothermic. Insects obtain heat from the environment instead of having to create their own body heat like typical mammals do. Furthermore, feeding insects is cheap. Organic waste can for example feed large populations of insect larvae. Due to ail these advantages, insect farming is gaining popularity. Besides being a good source of protein, insects also hâve a high nutritional value, probiotic potential and affordable price. Furthermore, they can hâve high concentrations of amino acids and certain vitamins such as vitamin B12, riboflavin, and vitamin A.

Many insects which hâve maggot and/or larval stages are suitable for insect farming. Mature larvae of different types of insects can be used as protein rich food for animais or humans. For example larvae from the Pachnoda marginata, also referred to as the Pachnoda butana, a beetle from the subfamily Cetoniina. Other examples may include:

- the Alphitobius diaperinus, a species of beetle in the family Tenebrionidae,

- the Zophobas morio, a species of darkling beetle, whose larvae are known by the common name superworm or zophobas,

- the mealworm beetle, Tenebrio molitor, a species of darkling beetle, the larvae being known as mealworms,

- the housefly, Musca domestica, is a fly of the suborder Cyclorrhapha, which larvae are known as maggots,

- Hermetia illucens, the black soldier fly, is a common and widespread fly,

- grasshoppers, insects of the order Orthoptera, suborder Caelifera,

- crickets family Gryllidae (also known as true crickets), are insects related to grasshoppers, well-known species of this family are Gryllus campestris (field cricket), Acheta domesticus (house cricket), and Gryllodes sigillatus (banded cricket),

- other insects such as Bombyx mori, Achroia girsella, Schistocerca americana 10 gregaria, Galleria mellonella, Locusta migratoria migratorioides.

Most of these insects are holometabolous insects, i.e. including four life stages - as an embryo or egg, a larva, a pupa, and an imago or adult. The first stage is from the fertilization of the egg inside the mother insect until the embryo hatches. The insect starts as a single cell and then develops into the larval form before it hatches. The 15 second stage lasts from hatching or birth until the larva pupates. In most species this mobile stage is worm-like in form, and these larvae are thus frequently referred to as “worms”. The third stage is from pupation until éclosion. In préparation for pupation, the larvae of many species construct a protective cocoon of silk or other material, such as its own accumulated faeces. In this stage, the insect's physiology and functional 20 structure, both internai and extemal, change drastically. Adult holometabolous insects usually hâve wings and functioning reproductive organs. In principle, the insects are harvested when the larvae are mature, i.e. nearthe end of the second stage, just before they turn into a pupa.

Culturally influenced aversion may resuit in some consumers being unwilling to 25 eat an insect-based product, or even to feed such a product to an animal. Therefore, processes in which insects are abstracted to food products with a non-insect appearance are favourable. As a simple example, grinding larvae removes their insect appearance, but results in an untextured slurry which consumers find unappealing to use in food applications. EP 2953487 A1 for example therefore discloses a process in 30 which insects after pulping are converted into nutrient streams, such as a fat-containing, an aqueous protein-containing and a solid-containing fraction. These nutrient streams may serve as ingrédients in further feed and food préparations. The disclosed process is rather complex, as different products hâve to be separated, processed, packed and distributed.

It would be advantageous to convert the entire insect into a single product, containing most to ail ofthe nutrients ofthe insect. As indicated, pulped larvae as such are unappealing and difficult to use in food products, in large part due to the untextured properties ofthe slurry. The addition of gelling agents to the pulped larvae may alleviate this problem. A process is commonly known in which a solution of calcium ions is poured into a slurry of ground larvae, alginate and water. Upon contacting the calcium ions, the alginate immediately gelâtes together with the ground larvae. This results in large clumps and aggregates, in which the centre consists of ungelated slurry. This is undesirable. Instead, a flake like structure is desired in which substantially ail hydrocolloid has been gelated with the métal cations. Therefore, during the addition of the calcium ion solution, the slurry should be vigorously stirred in a very spécifie fashion. Until now, the only solution was stirring by hand by a thereto trained operator. It goes without saying that such a process is unsuitable for upsealing, let alone for continuous production.

It is an objective ofthe présent invention to alleviate one ofthe abovementioned disadvantages or at least to provide a useful alternative. It is a further objective of the présent invention to provide a process for producing a textured· edible protein product derived from insect larvae or worms, in which substantially ail of the insect larvae or worms are converted into a single edible product. It is a further objective ofthe présent invention to provide a process for producing a textured edible protein product which process is scalable. It is a further objective ofthe présent invention to provide a process for producing a textured edible protein product in which process flakes ofthe textured edible protein product can be obtained without the interférence of an operator. It is a further objective ofthe présent invention to provide a process for producing a textured edible protein product which process is continuous. It is a further objective of the présent invention to provide a textured edible protein product derived from insect larvae or worms.

Description ofthe invention

In orderto reach at least one ofthe objectives, the présent invention provides a process for producing a textured edible protein product derived from insect larvae or worms. The process comprises the following steps:

a) reducing the insect larvae or worms in size to obtain a pulp,

b) mixing the pulp with a hydrocolloid that gelâtes with métal cations in aqueous solution to form a protein-hydrocolloid slurry,

c) injecting the protein-hydrocolloid slurry into an aqueous solution of a métal cation with a valency of at least 2 to form the textured edible protein product, wherein in the injecting in step c) the protein-hydrocolloid slurry is jetted under pressure from outside of the aqueous solution of a métal cation with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution, thereby producing flakes of the textured edible protein product in the aqueous solution, in which flakes substantially ail hydrocolloid has been gelated with the métal 10 cations.

The présent invention further provides a system for continuously producing a textured edible protein product derived from insect larvae or worms. The system comprises:

- a reaction vessel for holding an aqueous solution of a métal cation with a valency of at least 2,

- a réservoir for holding a protein-hydrocolloid slurry, said réservoir having an outlet in fluid communication with a pump and nozzle configured to inject a pressurized stream of the protein-hydrocolloid slurry from outside of the aqueous solution of a métal cation 20 with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution,

- a controlled supply means forfeeding métal cation into the reaction vessel for keeping a constant concentration of the métal cation in the aqueous solution,

- a separator for separating the edible protein product from the aqueous solution,

- a rinsing unit for rinsing the separated edible protein product,

- a dewatering press for dewatering and compacting the rinsed edible protein product.

The présent invention further provides a textured edible protein product derived from insect larvae or worms obtainable by the method of the invention.

In the process according to the invention, instead of adding the solution of the métal cation with a valency of at least 2 to the protein-hydrocolloid slurry, the slurry is jetted under pressure from outside of the aqueous solution of a métal cation with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution. Due to this process, flakes of the textured edible protein product are formed in the aqueous solution, in which flakes substantially ail hydrocolloid has been gelated with the métal cations. In other words, it is due to the injection from outside of the aqueous solution of the métal cation onto the liquid surface of the aqueous solution and subsequently into the aqueous solution and at an oblique angle to the liquid surface of the aqueous solution, that flakes can be formed in which substantially ail hydrocolloid has been gelated with the métal cations. Such flakes are not formed when injection is performed at a substantially perpendicular angle to the liquid surface, such as a bath surface, or the surface of a falling film, or when injection is performed directly into the solution of the métal cation, rather than from outside of the solution, i.e. not Crossing the air-liquid interface. In the case of direct injection, strands of gelated material are formed instead of flakes. The strands may even hâve a liquid core in which the hydrocolloid has not been gelated. The hydrocolloid on the outside of such strands has been gelated with the métal cation, thereby forming a skin through which further métal cations could not reach the centre of the strand. Such strands do not hâve sufficient texture. In the case of a substantially perpendicular angle, undesirable blob like structures are formed, which may also hâve a liquid core in which the hydrocolloid has not been gelated. This as opposed to the flakes of the présent invention, in which substantially ail hydrocolloid has been gelated with the métal cations. In this respect “substantially ail hydrocolloid has been gelated can be read as “not comprising a liquid core”.

When injection is substantially parallel to the liquid or bath surface, the slurry does not sufficiently cross the air-liquid interface and may bounce off the liquid surface. Even if the air-liquid interface is crossed, then flakes are not adequately formed.

Instead, small particles are formed.

Although the mechanism is not known, it is speculated that the impact of the injected slurry into the liquid surface, thereby breaking the surface tension, and then through the aqueous solution causes a turbulence that brakes up the jet of injected slurry, thereby forming flakes of slurry in which the hydrocolloid gelâtes with the métal cation. The métal cations can penetrate into the centre of the flakes before a skin of gelated hydrocolloid has been formed on the outside of the flakes. The required turbulence is only created if the angle is oblique.

An additional advantage of the process and System according to the invention, is that the métal cation solution is physically separated from the opening, such as a nozzle, through which the slurry is discharged. This prevents the métal cation solution from entering the part of the setup in which the slurry résides, and thereby largely éliminâtes the risk of clogging of equipment due to prematurely gelated hydrocolloid.

Description of embodiments

Insect larvae or worms are rich in proteins and sometimes fats. Therefore, they represent a relatively high calorie value. Preferably, edible insect larvae or worms are used. More preferably, the insect larvae are larvae of flies, bugs, mosquitos, butterflies, moths, cicadas, termites, bees, ants, wasps, beetles, grasshoppers, or crickets.

Preferably, the insect larvae or worms are selected from the group constituted by Tenebrio molitor, Hermetia illucens, Galleria mellonella, Alphitobius diaperinus, Zophobas morio, Blattera fusca, Tribolium castaneum, Rhynchophorus ferrugineus, Musca domestica, Chrysomya megacephala, Locusta migratoria, Schistocerca gregaria, Acheta domestica, Samia ricini or mixtures thereof.

More preferably, the insect larvae are larvae of beetles. Preferably, the beetles belong to the families of the Tenebrionidae, Melolonthidae, Dermestidae, Coccinellidae, Cerambycidae, Carabidae, Buprestidae, Cetoniidae, Dryophthoridae, or mixtures thereof. Still more preferably, the beetles are Tenebrio molitor, Alphitobius diaperinus, Zophobas morio, Tenebrio obscurus, Tribolium castaneum and

Rhynchophorus ferrugineus, or mixtures thereof.

Still more preferably, the beetles are larvae of Tenebrio molitor or Alphitobius diaperinus, most preferably, Alphitobius diaperinus.

The insects or worms are preferably cultivated, e.g. in an insect farm. The cultivation allows to control and reduce the risks associated with diseases of insects and with the toxicity of insect-derived foodstuffs, e.g. due to the presence insecticides, in contrast to insects harvested in nature.

Cultivated worms and larvae as well as those harvested in nature comprise dirt, such as left-over feed, manure and shedded skin. In préparation of the process according to the invention, i.e. before step a), the harvested insect larvae or worms are therefore preferably cleaned, for example by washing them with water, preferably soft water. They may be rinsed or they may be submerged in water, preferably soft water, after which the excess water is drained. Any remaining water sticking to the insect larvae or worms after washing can be removed, but this is not necessary. A small amount of water sticking to the larvae or worms, or even some extra water added to the larvae or worms before executing step a) may even aid in the size réduction process. Typically, about 15-20 wt% of water, such as about 17 wt% with respect to the larvae weight sticks to the larvae after washing if no steps are taken to remove 5 water after washing and draining the washing water. This corresponds to 13 - 17 wt%, such as 15% based on the weight of larvae and water combined. If extra water is added to the larvae or worms before size réduction step a), then preferably, the water is soft water. Preferably, before the size réduction step a), the larvae or worms are combined with 10-90 wt%, preferably 25- 75 wt%, more preferably 35 -65 wt%, most preferably 10 40-60 wt% of water, based on the weight of the larvae or worms (this water includes both extra added water and/or sticking water from washing). It is especially preferred that any water used in the process in or before steps a) and/or b) is soft water. The term soft water is known in the art. Soft water comprises no, or a minimalized amount of multivalent cations. It may be obtained by treatment of water with an ion exchange 15 resin, by addition of softening salts such as a combination of tetrasodium pyrophosphate (TSPP) with NaCI, and other softening methods known in the art. This prevents early gélation of the hydrocolloid.

In a preferred embodiment, the insect larvae or worms are cleaned with water 20 with a température of at least 60 °C, such as between 60 - 95 °C, for about 1 - 5 minutes, such as about 2-3 minutes, after which excess water is drained. This kills and cleans the larvae at the same time. In a preferred embodiment, the water is drained while continuously rinsing the larvae with fresh water. Alternatively, the larvae are submerged in the cleaning water, after which the water is drained.

In the process, one or more antioxidants may be added, for example to the cleaned insect larvae or worms, their pulp, or to the protein-hydrocolloid slurry. Many food and/or feed approved antioxidants are known. Antioxidants comprise synthetic antioxidants as well as natural antioxidants. Natural antioxidants are preferred, in large 30 part due to their réputation as being from natural origin, and therefore “ail natural”, which is more appealing for consumers. Natural antioxidants include (with European additive and/or feed additive identification number between brackets) ascorbic acid (3a300, E300), tocopherols (E 306, 308, 309), tocopherol extracts from vegetable oils (1b306(i)), tocopherol-rich extracts from vegetable oils (delta rich), alpha-tocopherol (1b307), tocotrienol, rosemary extract (E 392), gallic acid, carnosic acid, garlic extract, olive extract rich in phenolic compounds, and catechins-rich tea extract. Rosemary extract (i.e. rosemary oil) is especially preferred. The antioxidant may be added in an effective amount, for example from about 0.1 - 100 g/kg larvae, such as from 1-10 5 g/kg larvae.

In step a), the insect larvae orworms, optionally with water as mentioned earlier (sticking water and/or extra added water), are reduced in size to obtain a pulp. For example, they may be mashed, grinded, squashed, eut, mixed and/or milled to obtain 10 the pulp. This results in a homogeneous starting material of viscous consistency. The reducing in size can conveniently be performed in a high shear mixer, although other suitable techniques can also be used. High shear mixers are well known in the art.

During the size réduction step, the particle size of the insect larvae orworms in the pulp is preferably reduced to less than 2 mm (the largest size to be determined 15 using a microscope or using laser diffraction), more preferably less than 1 mm, even more preferably less than 0.5 mm. The smaller the particle size, the better, i.e. less grainy, the mouthfeel. The particle size can be controlled by sélection of mixing time and speed. A skilled person can fmd suitable conditions in order to reach a desired particle size. In a preferred embodiment, the particle size is in the range of 0.1 - 1 mm. 20

Before, after or during mixing, the insect larvae or worms, the pulp or a pulpwater mixture may be heated at a température above 85 °C, such as between 85 and 100 °C for at least 3 minutes, such as about 3-5 minutes, for pasteurization purposes. Pasteurization however may also be performed later in the process, such as during or 25 after step b), or even after step c). For example, after formation, the flakes of the textured edible protein product may be heated at a température above 85 °C, such as between 85 and 100 °C for at least 3 minutes, such as about 3-5 minutes. Preferably, pasteurization is performed before step b) in order to prevent caking of the equipment.

A solution of hydrocolloid in water, preferably soft water, may be prepared by dissolving the hydrocolloid in water, preferably with the aid of a mixer. The water in which the hydrocolloid is dissolved may provide the water for forming the aqueous solution in step b), or in case waterwas already added to the larvae orworms it provides extra water for forming the aqueous solution. Though the water does not need to be heated, heating the water to a température of between 50-100 °C, such as about 60

C speeds up the dissolution process. A typical hydrocolloid concentration after dissolution is 3.5 - 4 % (w/v). The hydrocolloid that gelâtes with métal cations may be selected from pectin with a low methoxyl group content, Gellan gum and alginate; of these, sodium alginate is preferred.

The solution of hydrocolloid in water is subsequently mixed with the pulp. This forms the protein-hydrocolloid slurry. The mixing may again take place at a température of between 50-100 °C, such as about 60 °C. Preferably, the hydrocolloid that gelâtes with métal cations is présent in a quantity of from 0.5 - 20 wt%, preferably of from 2 10 wt%, most preferably of from 4.5 - 5 wt% based on the weight of the larvae. Preferably, the protein-hydrocolloid slurry comprises from 10-75 wt% of larvae, more preferably from 20 - 50 wt%, even more preferably from 30 - 40 wt%, based on the combined weight of larvae, water and hydrocolloid. At lower amounts of larvae, the solution is not concentrated enough, and flakes are not adequately formed. At too high amounts of larvae, the solution is too viscous and cannot be adequately processed.

Depending on the hydrocolloid that gelâtes with métal cations which is used, it may be necessary to adapt the pH of the slurry prior to mixing with the solution of métal cations with a valency of at least 2. Preferably, the pH is in the range from 6-8.

Preferably, the aqueous solution of a métal cation with a valency of at least 2 contains soluble calcium or magnésium salts or mixtures thereof, preferably calcium chloride, calcium acetate, calcium lactate and/or calcium gluconate, such as calcium chloride, calcium acetate and/or calcium gluconate, most preferably calcium lactate and/or calcium chloride, still more preferably calcium chloride ; although other calcium or magnésium salts which are permitted for use in the food industry can also be used. Calcium chloride is preferred because of the gélation speed. Use of sait other than calcium chloride generally decreases the speed of formation of the flakes. Calcium lactate is also particularly advantageous because it avoids formation of chloride sodium during the formation of flakes.

Upon préparation of the aqueous solution of a métal cation, it is advantageous to dissolve the métal cation with a valency of at least 2 in water at the same température as the protein-hydrocolloid slurry. The concentration of métal cations used in the gélation solution (i.e. the aqueous solution of a métal cation) is generally, for example in the case of calcium chloride, from 0.1 - 15% (w/v), expediently 0.1 - 5% (w/v) and preferably 0.5 - 5% (w/v). Generally, at high concentrations, the gélation process is faster, whereas at concentrations that are too low (i.e. less than 0.1 wt%), there is less cohésion within the flakes and/or a skin may be formed on the outside with ungelated hydrocolloid remaining inside of the flakes.

Preferably, the concentration of the métal cation with a valency of at least 2 in the aqueous solution is kept constant during injection step c). In this respect, constant means not varying more than 1 % (w/v) higher or lower. Thus, if the value of the constant métal cation concentration is chosen to be 4% (w/v), then the concentration may vary from 3 - 5% (w/v).

Preferably, a concentrated métal cation solution is prepared and added to the aqueous solution of métal cation during the injection step c), for keeping the concentration in the métal cation solution constant during gélation of the product (flakes).

The protein-hydrocolloid slurry is then jetted under pressure from outside of the aqueous solution of a métal cation with a valency of at least 2 into the aqueous solution of métal cation at an oblique angle with respect to a liquid surface of the aqueous solution, thereby producing flakes of the textured edible protein product in the aqueous solution, in which flakes substantially ail hydrocolloid has been gelated with the métal cations. Substantially ail in this case can be read as meaning that more than 90 wt% of the hydrocolloid in the flakes has been gelated, preferably more than 95 wt%. Thus, the weight fraction of hydrocolloid in the flakes that is soluble in soft water is less than 10 wt%, preferably less than 5 wt%, based on the total weight of the hydrocolloid in the flakes.

By breaking the surface tension of the aqueous solution that contains métal cations with a valency of at least 2 and further entry of the slurry into the aqueous solution, flakes are formed, which, starting at their surface, are set through gélation of the hydrocolloid with métal cations. Due to the breaking of the surface tension and subséquent entry into the aqueous solution, the ratio of surface area vs. volume of the formed flakes is large enough that the flakes do not contain ungelated hydrocolloid. Without this breaking ofthe surface tension, the skin of gelated hydrocolloid and worm or larvae material formed on the gelated structures may form a barrier to diffusion of

métal cations to the interior of the structures, thus creating slurry-filled blob like structures.

Thus, flakes of the textured edible protein product are formed in the aqueous 5 solution, in which flakes substantially ail hydrocolloid has been gelated with the métal cations.

In an embodiment, it is envisaged thatthe aqueous solution ofthe métal cation is présent as a bath. The oblique angle (a) is then measured as the angle between the plane that is formed by the liquid surface ofthe aqueous solution ofthe bath and the 10 smallest angle with the protein-hydrocolloid slurry jet at the point of impact.

In another embodiment, the aqueous solution of the métal cation is présent in the form of a falling film. This film may be a free-falling film, but preferably the film flows/falls along a surface. The oblique angle of a falling film is measured as the angle between the plane that is formed by the liquid surface ofthe film and the angle with the 15 protein-hydrocolloidslurryjetâtthepointof impact, with injection along theflowof liquid having an angle < 90 °, and injection against the flow of liquid having an angle > 90 °. Injection along the flow of liquid is preferred.

Preferably, the oblique angle has a value of between 10 - 60 °, preferably between 15-50 °, more preferably between 20 - 40 °. This has been found the 20 optimum angle. At too small angles, the slurry may bounce of the liquid surface and/or too small structures are formed, whereas at too high angles, blob like structures instead of flakes are formed, in which blob like structures not ail hydrocolloid has gelated. The optimum angle has been found to be largely independent from the used pressure, । throughput and nozzle diameter.

Preferably, jetting under pressure is performed through an opening, preferably a nozzle, more preferably a nozzle with a diameter of between 0.1 - 10 mm, preferably 1-5 mm.

When performed through a nozzle, preferably, the jetting under pressure is performed at a constant pressure in the nozzle, i.e. a pressure not varying more than i 30 0.1 bar in either direction. Preferably, the value ofthe constant pressure is between 0.2

- 0.7 bar overpressure, more preferably between 0.3 - 0.6 bar overpressure, most preferably between 0.4 - 0.5 bar overpressure. Thus, if the value of the constant pressure is chosen to be 0.5 bar overpressure, then the pressure may vary from 0.4 0.6 bar overpressure.

Advantageously, the nozzle is a laminarflow nozzle, also named laminar nozzle.

Preferably, the protein-hydrocolloid slurry is jetted with a débit between 100 400 l/h, more preferably between 200 - 300 l/h, such as 250 l/h. When several nozzles are used, such a débit is preferably the débit of each nozzle.

Due to injection of the protein-hydrocolloid slurry into the aqueous métal cation solution (i.e. aqueous solution of a métal cation with a valency of at least 2), and subséquent gélation of the hydrocolloid with the métal cations in the solution, the remaining concentration of the métal cation in the aqueous solution in the reaction 10 vessel is reduced. In order to counteract this déplétion of ions, fresh métal cation may be fed to the aqueous métal cation solution in order to keep the métal cation concentration in the aqueous métal cation solution constant. This may for example be achieved by feeding a concentrated aqueous solution of a métal cation with a valency of at least 2 into the aqueous métal cation solution. In this respect, concentrated means 15 a concentration which is higher than the concentration of the métal cation in the aqueous métal cation solution.

After formation, the flakes of the edible protein product may be separated from the aqueous solution, for example continuously, such as by a wire mesh conveyor, or 20 batchwise, by scooping the edible protein product from the aqueous solution. The remaining aqueous solution comprises soluble proteins. If desired, the soluble proteins may be extracted from the remaining aqueous solution to form an additional nutrient stream.

After séparation, preferably, the flakes of the edible protein product are preferably rinsed with water in order to wash out métal cations with a valency of at least 2 that hâve not yet reacted with hydrocolloid. Thorough rinsing with water, such as tap water, causes the métal cations that are présent in excess to be rinsed out of the flakes.

After rinsing, preferably, the rinsed flakes of the edible protein product are dewatered, such as with a centrifuge, but preferably with a dewatering press, more preferably a dewatering screw press, and preferably to a moisture content of 50 - 90 wt%, more preferably 60 - 90 wt%.

The resulting material may be eut into adequately handleable pièces, and then packaged for transport. If not performed earher m the process, the fibre-comprismg food product according to the invention may be subjected to a treatment with a germicidal action after it has been packaged. A treatment with a germicidal action can then be selected from pasteurization, sterilization, and treatment with radiation.

Brief description of the drawings

Fig. 1 represents a schematic picture of a system according to the invention.

Fig. 2 represents a schematic picture of the oblique angle a in different embodiments.

Detailed description of drawings

Fig. 1 represents a schematic picture of a system 1 for continuously producing a textured edible protein product derived from insect larvae or worms according to the invention. The system 1 comprises

- a reaction vessel 15 for holding an aqueous solution of a métal cation with a valency of at least 2,

- a réservoir 8 for holding a protein-hydrocolloid slurry, said réservoir 8 having an outlet 24 in fluid communication with a pump 16 and nozzle 18 configured to inject a pressurized stream of the protein-hydrocolloid slurry from outside of the aqueous solution of a métal cation with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution,

- a controlled supply means 25 for feeding métal cation into the reaction vessel 15 for keeping a constant concentration of the métal cation in the aqueous solution,

- a separator 19 for separating the edible protein product from the aqueous solution,

- a rinsing unit 22 for rinsing the separated edible protein product, and

- a dewatering press 23 for dewatering and compacting the rinsed edible protein product.

The réservoir 8 may be any type of réservoir suitable for holding the proteinhydrocolloid slurry. Advantageously, the réservoir 8 comprises mixing means and heating means. The réservoir 8 may further comprise an inlet 2 for the pulp, and an inlet 3 for soft water. The réservoir 8 may further comprise inlet 7 for the aqueous hydrocolloid solution, which may for example be fed by an aqueous hydrocolloid dispensing unit 6. Advantageously, the dispensing unit 6 comprises mixing means and heating means. The dispensing unit 6 is preferably fed by a soft water inlet 5 and a hydrocolloid powder dispensing unit 4.

The pump 16 and nozzle 18 preferably comprise a pressure control unit 17 for controlling the pressure ofthe pressurized stream ofthe protein-hydrocolloid slurry. The nozzle may be located above, diagonally above, or in the reaction vessel 15, as long as the nozzle opening is not in direct contact with the liquid when présent in the reaction vessel 15. In a preferred embodiment, outlet24 is in fluid communication with multiple combinations of pumps and nozzles, for simultaneously injecting multiple pressurized streams of the protein-hydrocolloid slurry, and thereby increasing the production capacity. Preferably, the System comprises at least one nozzle, preferably between 1 and 10 nozzles 18, more preferably between 2 and 8 nozzles 18, most preferably between 4 and 6 nozzles 18. If the System 1 comprises more than 1 nozzle 18, the nozzles 18 are implemented in parallel and preferably, the nozzles 18 share the same reaction vessel 15.

The reaction vessel 15 can be fed with the aqueous solution of a métal cation by controlled supply means 25. Controlled supply means 25 may for example comprise a réservoir 11 for holding a concentrated aqueous solution of a métal cation, which réservoir 11 further comprises an outlet 12, which is controlled by an ion sensor 14 in communication with valve 13. Advantageously, the réservoir 11 comprises mixing means and heating means. The réservoir 11 may further comprise a water inlet 9, which may be a tap water inlet, and a solid métal cation dispensing unit 10. When the ion sensor 14 detects that the ion level falls below a setpoint value, it may cause valve 13 to open and allow a sufficient amount of concentrated aqueous solution of métal cation to supplément the métal cations in the reaction vessel 15 through outlet 12.

The reaction vessel 15 advantageously comprises an outlet 21 for draining excess aqueous solution into drain unit 20. The reaction vessel 15 furthermore advantageously comprises an inlet 31 for soft water.

In a preferred embodiment, reaction vessel 15 comprises a means for creating a falling film of the aqueous solution of métal cation. The falling film may be free standing, or flowing along a surface 30. Surface 30 may be a vertical surface, or it may be inclined, preferably at an angle less than 90 °. The means for creating a falling film may for example include a pump and vertical or inclined surface. In a particularly advantageous embodiment, the falling film falls onto separator 19.

The separator 19 for separating the edible protein product from the aqueous solution may for example be a wire mesh conveyor. However, the separator can also be a paddle wheel or any other suitable separating means. The rinsing unit 22 may comprise one or multiple nozzles fed by a water supply in order to rinse the separated edible protein product.

The rinsing unit 22 is advantageously located above drain unit 20.

The inlet 26 of the dewatering press 23 is advantageously fed by the separator 19.

The dewatering press 23 may for example be a cheese press. Cheese presses are known in the art. However, preferably the dewatering press is a dewatering screw press. Dewatering screw presses are known in the art. They are slow moving devices that accomplish dewatering by continuous gravitational drainage. The screw press squeezes the material against a screen or filter and the liquid is collected through the screen.

Such a press usually consists of an inlet opening, a transport and press screw, a press section and an outlet. Forwet materials, the press may be fitted with a sieve to drain the water. The screw transports the material to dewater from the inlet opening into to the press area. At the location of the press area, the screw blade is preferably adapted for compacting, that is, the screw blade may e.g. welded with a wear-resistant layer and the pitch is smaller than in the conveying part. The outlet is equipped with one or more controlled valves (e.g. pneumatically) with which the discharge pressure can be set. The supplied material to dewater is put under an increasing pressure by the rotating screw conveyor, which reduces the volume. The outlet valves open further and further when the set discharge pressure is reached and the compressed roll of material is slowly expelled.

The System 1 is adapted to perform the process for producing a textured edible protein product derived from insect larvae or worms according to the invention. Thus, this System advantageously présents the advantageous and preferred features and ernbodiments disclosed in the process.

' Fig. 2a depicts the oblique angle a of the nozzle 18 with respect to the liquid surface 27 of the liquid in reaction vessel 15.

Fig. 2b depicts the oblique angle a of the nozzle 18 with respect to the liquid surface 27 of a liquid film which flows in direction 19 along surface 30 into the reaction 5 vessel 15.

Experiment

Larvae of Alphitobius diaperinuswere harvested (23 kg) and submerged in water with a température of between 55 and 60 °C for a maximum of 3 minutes to 10 simultaneously wash and kill the larvae, after which the larvae were separated from the water. Any water still sticking to the larvae after séparation was not removed. The larvae were combined with 10 kg of soft water from a soft water supply, and subsequently, the larvae were reduced to a size of about 0.5 mm with a blender, thereby forming a pulp.

Then, 30 g of rosemary oil was added to the pulp, and further mixing was 15 performed with the blender.

Alginate (1125 g = 48,9 g/kg of larvae) was dissolved in 36 kg of soft water of about 80 °C. The warm alginate solution and pulp were combined and mixed by stirring at a température of about 60 °C to form a slurry.

In a bath, 250 g of CaCI2 was dissolved in 10 kg of water of 90 °C at a 20 concentration of about 2.5% w/v. The alginate-larvae slurry was fed to a pump which was connected to a nozzle with a diameter of about 2 mm and sprayed into the bath under an angle of 30 ° with an overpressure of about 0.5 bar. Flakes of the protein product were immediately formed upon impact with the CaCI2 solution. After ail of the slurry was gelated, the solution was heated to above 90 °C for 3 minutes for 25 pasteurization. Subsequently, the flakes were collected and washed twice with cold water. Dewatering was performed with a cheese press, and the resulting blocks of product were eut, vacuum-packed and stored in the freezer.

Claims (15)

1. Process for producing a textured edible protein product derived from insect larvae or worms, the process comprising the following steps:

a) reducing the insect larvae or worms in size to obtain a pulp,

b) mixing the pulp with a hydrocolloid that gelâtes with métal cations in aqueous solution to form a protein-hydrocolloid slurry,

c) injecting the protein-hydrocolloid slurry into an aqueous solution of a métal cation with a valency of at least 2 to form the textured edible protein product, wherein in the injecting in step c) the protein-hydrocolloid slurry is jetted under pressure from outside of the aqueous solution of a métal cation with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution, thereby producing flakes of the textured edible protein product in the aqueous solution, in which flakes substantially ail hydrocolloid has been gelated with the métal cations.

2. Process according to claim 1, wherein the oblique angle has a value of between 10 - 60 °, preferably between 15 - 50 °, more preferably between 20 - 40 °.

3. Process according to claim 1 or 2, wherein jetting under pressure is performed through an opening, preferably a nozzle, more preferably a nozzle with a diameter of between 0.1-10 mm, most preferably 1-5 mm.

4. Process according to any one of the previous daims, wherein the hydrocolloid that gelâtes with métal cations is sodium alginate.

5. Process according to any one of the previous daims, wherein the aqueous solution of a métal cation with a valency of at least 2 contains soluble calcium or magnésium salts or mixtures thereof.

6. Process according to any one of the previous daims, wherein a concentration of the métal cation in the aqueous solution is kept constant.

7. Process according to any one of the previous daims, wherein the hydrocoiloid that gelâtes with métal cations is présent in a quantity of from 0.5 - 20 wt%, preferably offrom 2 - 10 wt%, most preferably offrom 4.5 - 5 wt% based on a weight ofthe insert larvae or worms.

8. Process according to any one of the previous daims, wherein the proteinhydrocolloid slurry comprises from 10-75 wt% of the insect larvae or worms, more preferably from 20 - 50 wt%, even more preferably from 30 - 40 wt%, based on the combined weight ofthe insect larvae orworms, water and hydrocoiloid.

9. Process according to any one of the previous daims, wherein the aqueous solution of a métal cation with a valency of at least 2 is présent as a bath and the liquid surface ofthe aqueous solution is a bath surface, or wherein the aqueous solution of a métal cation with a valency of at least 2 is 15 présent as a falling film, and the liquid surface of the aqueous solution is a surface of the falling film.

10. Process according to any one of the previous daims, wherein the flakes of the edible protein product are separated from the aqueous solution.

11. Process according to any one of the previous daims, wherein the flakes of the edible protein product are rinsed with water to remove excess métal cations.

12. Process according to daim 11, wherein the rinsed flakes of the edible protein 25 product are dewatered, preferably with a dewatering press, more preferably a dewatering screw press, and preferably to a moisture content of 50 - 90 wt%, more preferably 60 - 90 wt%.

13. System (1) for continuously producing a textured edible protein product derived 30 from insect larvae or worms, the System comprising:

- a reaction vessel (15) for holding an aqueous solution of a métal cation with a valency of at least 2,

- a réservoir (8) for holding a protein-hydrocolloid slurry, said réservoir (8) having an outlet (24) in fluid communication with a pump (16) and nozzle (18) configured to inject a pressurized stream of the protein-hydrocolloid slurry from outside of the aqueous solution of a métal cation with a valency of at least 2 into the aqueous solution at an oblique angle with respect to a liquid surface of the aqueous solution,

- a controlled supply means (25) forfeeding a métal cation into the reaction vessel (15) 5 for keeping a constant concentration of the métal cation in the aqueous solution,

- a separator (19) for separating the edible protein product from the aqueous solution,

- a rinsing unit (22) for rinsing the separated edible protein product,

- a dewatering press (23) for dewatering and compacting the rinsed edible protein product.

14. System according to claim 13, wherein the outlet (24) is in fluid communication with multiple combinations of pumps and nozzles, for simultaneously injecting multiple pressurized streams of the protein-hydrocolloid slurry.

15 15. Textured edible protein product derived from insect larvae or worms obtainable by the process according to any one of claims 1-12.